344 
95 to 100 ; whereas, that of the heavieft 
hydro-carbonat amounts to no more than 
67.—2. When mixed with common air it 
dees not explode, but burns with a lambent 
blue flame.— 3. The product of the com- 
buftion is carbonic acid, without any per- 
ceptible quantity of water.—4. For the 
converfion of’ this-gas into carbonic acid, 
only 40 per cent. of oxygen is requifite.— 
‘Hence this gas is effentially different from 
the hydre-earbonats in the total abfence of 
hydrogen ; it confilts of 21 oxygen, and 
about 9 earbon; may be properly called 
the gafleous oxyd of carbon, as it bears 
the fame relation to carbonic acid as the 
gafieous oxyd of azot does to nitrous acid. 
‘The inferences of Dr.P. eflentially depend- 
ing on the fuppofed prefence of hydrogen in 
this gas, are of confequence unfounded. 
A work, entitled Confiderations on the 
Deaf and Dumb, and the Means of render- 
ing them fufceptible of Speech, by AGtion, 
&c. by U.R.S. Le Bouvyer Des- 
MORTIERS, has been lately produced. 
‘This treatife is worthy the confideration 
of every individual who feels interefted in 
the development of the faculties of thofe 
whom Nature feems to have forgotten. The 
AbbeDEL’Epe’s, inventor of this {cience, 
and his ftudent,C.S1c arp, who brought it 
to creater perfection, fhonld be placed amid 
the {mall number of thefe who have proved 
themfelves friends to humanity. C. Def- 
mortiers, though but one of their fol- 
lowers, equally merits applaufe, as his 
werk prefents ina new light, the means of 
inftruG@ting the deaf and dumb, and gives 
very fatisfactory proofs as to his theery. 
At Eafer, Profefior TroMMeporr, 
ef Erfurt, in Saxony, in conjunction with 
ether eminent German chemifts, be- 
gan to publith an Allgemeine Bibliothek der 
Chemilchen Literatur ; or, General Library 
of Chemicai Literature. The objeé&t cf 
this publication is to make his readers ac- 
guainted with all the chemical works that 
fhall appeat in Germany or elfewhere, and 
to give a general view of the progrefs of 
the icience of chemiftry, the frudy of which 
is now purfued with fuch ardour. 
The illumination of rotten’ wood has 
been of latea fubjeét of inquiry and dif- 
euffion amongft naturalifts. Thelate M. 
SPALLANZaANI maintained, that there is a 
perie&t analogy between the iliumination 
of rotten wood, and the artificial phofpho- 
rus ; and he imagines, that in the putrid 
fermentation, the hydrogen and the carbon 
of the wood come more eafily in contaét- 
with the oxygen of the atmofphere, by 
which combination a flow combuftion, and 
‘the illumination of the wood,is produced ; 
and he at the jaime time tilinks,that this pro- 
- Eiterary and Philjephical Enteliigence. 
cefs cannot proceed in the irrefpirable kinds 
of gaffes. Rotten wood alfo, in which the 
neceflary, quantity of hydrogen and carbon 
is not at the fame time difengaged, does 
not obtain the property of illuminating. 
Mr, Conrapogi, however, objeés to this 
theory, that the flow combuftion does not 
take place according to the above theory, 
as the wood, at the time when it begins to 
illuminate,is moftly deprived of its refinous 
particles, and conlequently contains. but — 
very -little hydrogen and carbon; and it, 
;appears to him more probable, that the 
more it lofes of combutftible matter, the 
more it obtains the property of illuminat- 
ing. Theres, in fhort, he thinks, a very 
great ‘difference. between this natural and 
the artificial phofphorus. Mr. Hum: 
BOLD®Y concludes from his experiments, 
that the illumination of rotten wood takes 
place only when it gets in contaét with 
oxygen ; and when it has lof the property 
of emitting light in. irrefpirable gaffes, it 
-Fecovers it again by expofing it to oxygen 
gas. Dr. GarTNER, however, is of opi- 
nion that, according to his experiments, 
a certain degree cf humidity is always 
requifite; and he thinks, that oxygen.gas 
is not guite_neceflary, though the illumi- 
nation is increafed by it. This phenome- 
non, however, being ia very different from 
all known proceffes of combuftion, where 
light is difengaged, Dr. G&rtner afks,. 
whether it 1s net more agreeing with the. 
animal procefs of refpiration, than with a 
true combuftion, or whether the illumina- 
tion of the wood is produced by phofpho- 
rus and carbon in a pr@portion hitheite 
unknown. Dr. Gartner is, on the whole, 
inclined to think, that it is at prefent 
impoffible to give a fatisfadtory explana- 
tion of the all phenomena that occur-in this 
procefs. Mr. BoECKMANN has made nu- 
merous obfervations and experiments on 
the illumination of rotten wood, in different 
gafles and fluids, in order to throw fome 
light on the ideas of the above naturalifts. 
The refults of thefe experiments differ ia 
fome points frony what the experiments of 
thofe gentlemen have fhewn, which, how- 
ever, Mr. Boeckmann aicribes to the na- 
ture of rotten wood, as a fubftance that is 
_not always of the fame kind, and has fot 
always -an equal degree of putrefaction 
and humidity. It feems to differ likewife 
materially from the artificial phofphorus 
by the following diagnoftics. 1. It fhines 
in oxygen gas at a. very low temperature. 
2. It emits light in all irrefpirable gaffes, 
at leat for a fhort time. | 3. In, muriatie 
gas its light is {tuddenly  extinguifhed. 
4. It fhines in a lefs degree in air, rarified 
by the air-pump. 5. According to Mr. 
Corra- 
[May 2, 
